mmc: boot partition ro lock support
Enable boot partitions to be read-only locked until next power on via
a sysfs entry. There will be one sysfs entry for each boot partition:
/sys/block/mmcblkXbootY/ro_lock_until_next_power_on
Each boot partition is locked by writing 1 to its file.
Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: John Beckett <john.beckett@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index ad0fb8d..0c959c9 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -107,6 +107,8 @@
*/
unsigned int part_curr;
struct device_attribute force_ro;
+ struct device_attribute power_ro_lock;
+ int area_type;
};
static DEFINE_MUTEX(open_lock);
@@ -165,6 +167,70 @@
mutex_unlock(&open_lock);
}
+static ssize_t power_ro_lock_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int ret;
+ struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
+ struct mmc_card *card = md->queue.card;
+ int locked = 0;
+
+ if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PERM_WP_EN)
+ locked = 2;
+ else if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_EN)
+ locked = 1;
+
+ ret = snprintf(buf, PAGE_SIZE, "%d\n", locked);
+
+ return ret;
+}
+
+static ssize_t power_ro_lock_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ int ret;
+ struct mmc_blk_data *md, *part_md;
+ struct mmc_card *card;
+ unsigned long set;
+
+ if (kstrtoul(buf, 0, &set))
+ return -EINVAL;
+
+ if (set != 1)
+ return count;
+
+ md = mmc_blk_get(dev_to_disk(dev));
+ card = md->queue.card;
+
+ mmc_claim_host(card->host);
+
+ ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP,
+ card->ext_csd.boot_ro_lock |
+ EXT_CSD_BOOT_WP_B_PWR_WP_EN,
+ card->ext_csd.part_time);
+ if (ret)
+ pr_err("%s: Locking boot partition ro until next power on failed: %d\n", md->disk->disk_name, ret);
+ else
+ card->ext_csd.boot_ro_lock |= EXT_CSD_BOOT_WP_B_PWR_WP_EN;
+
+ mmc_release_host(card->host);
+
+ if (!ret) {
+ pr_info("%s: Locking boot partition ro until next power on\n",
+ md->disk->disk_name);
+ set_disk_ro(md->disk, 1);
+
+ list_for_each_entry(part_md, &md->part, part)
+ if (part_md->area_type == MMC_BLK_DATA_AREA_BOOT) {
+ pr_info("%s: Locking boot partition ro until next power on\n", part_md->disk->disk_name);
+ set_disk_ro(part_md->disk, 1);
+ }
+ }
+
+ mmc_blk_put(md);
+ return count;
+}
+
static ssize_t force_ro_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -1347,7 +1413,8 @@
struct device *parent,
sector_t size,
bool default_ro,
- const char *subname)
+ const char *subname,
+ int area_type)
{
struct mmc_blk_data *md;
int devidx, ret;
@@ -1372,11 +1439,12 @@
if (!subname) {
md->name_idx = find_first_zero_bit(name_use, max_devices);
__set_bit(md->name_idx, name_use);
- }
- else
+ } else
md->name_idx = ((struct mmc_blk_data *)
dev_to_disk(parent)->private_data)->name_idx;
+ md->area_type = area_type;
+
/*
* Set the read-only status based on the supported commands
* and the write protect switch.
@@ -1470,7 +1538,8 @@
size = card->csd.capacity << (card->csd.read_blkbits - 9);
}
- md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL);
+ md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL,
+ MMC_BLK_DATA_AREA_MAIN);
return md;
}
@@ -1479,13 +1548,14 @@
unsigned int part_type,
sector_t size,
bool default_ro,
- const char *subname)
+ const char *subname,
+ int area_type)
{
char cap_str[10];
struct mmc_blk_data *part_md;
part_md = mmc_blk_alloc_req(card, disk_to_dev(md->disk), size, default_ro,
- subname);
+ subname, area_type);
if (IS_ERR(part_md))
return PTR_ERR(part_md);
part_md->part_type = part_type;
@@ -1518,7 +1588,8 @@
card->part[idx].part_cfg,
card->part[idx].size >> 9,
card->part[idx].force_ro,
- card->part[idx].name);
+ card->part[idx].name,
+ card->part[idx].area_type);
if (ret)
return ret;
}
@@ -1547,9 +1618,16 @@
static void mmc_blk_remove_req(struct mmc_blk_data *md)
{
+ struct mmc_card *card;
+
if (md) {
+ card = md->queue.card;
if (md->disk->flags & GENHD_FL_UP) {
device_remove_file(disk_to_dev(md->disk), &md->force_ro);
+ if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
+ card->ext_csd.boot_ro_lockable)
+ device_remove_file(disk_to_dev(md->disk),
+ &md->power_ro_lock);
/* Stop new requests from getting into the queue */
del_gendisk(md->disk);
@@ -1578,6 +1656,7 @@
static int mmc_add_disk(struct mmc_blk_data *md)
{
int ret;
+ struct mmc_card *card = md->queue.card;
add_disk(md->disk);
md->force_ro.show = force_ro_show;
@@ -1587,7 +1666,33 @@
md->force_ro.attr.mode = S_IRUGO | S_IWUSR;
ret = device_create_file(disk_to_dev(md->disk), &md->force_ro);
if (ret)
- del_gendisk(md->disk);
+ goto force_ro_fail;
+
+ if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
+ card->ext_csd.boot_ro_lockable) {
+ mode_t mode;
+
+ if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_DIS)
+ mode = S_IRUGO;
+ else
+ mode = S_IRUGO | S_IWUSR;
+
+ md->power_ro_lock.show = power_ro_lock_show;
+ md->power_ro_lock.store = power_ro_lock_store;
+ md->power_ro_lock.attr.mode = mode;
+ md->power_ro_lock.attr.name =
+ "ro_lock_until_next_power_on";
+ ret = device_create_file(disk_to_dev(md->disk),
+ &md->power_ro_lock);
+ if (ret)
+ goto power_ro_lock_fail;
+ }
+ return ret;
+
+power_ro_lock_fail:
+ device_remove_file(disk_to_dev(md->disk), &md->force_ro);
+force_ro_fail:
+ del_gendisk(md->disk);
return ret;
}